Polydactyly Polydactyly is a condition in which a person has more than five fingers per hand or five toes per foot. Forms of Polydactyly consist of an extra bump at the side of your hand, a finger which widens to end in two fingertips, having five fingers with one thumb (which can seem to be normal from a distance) and an infinite amount of other combonations. The digits may or may not be with shared joints and vessels, nerves, bone etc. and feet / hands may not always be effected at the same time. Polydacyly is also reffered to as something called Supernumerary digits or extra digits. Polydactyly got its name from the ancient greek language, polus-daktulos; polus meaning many, daktulos meaning finger.
Symptoms
Physical problems assiosiated with poldactyly include fingers that are bigger than they should be (bigger than other fingers), Extra digits that are poorly developed and attached by a small stalk that can easily fall off, having problems with malformations inside the hand with the bones rather than having extra digits, or having digits that are smaller than they should be. Limitations consist of hands and feet not being able to fit inside some types of shoes and gloves/mittens, not being able to get a solid grip on certain things, and not being able to have a lot pressure on your hand otherwise, loose digits will fall off or damages can occur. As metioned in the last paragraph, there is almost an infinite amount of different malformation combinations that can occur. However, you can identify it in four ways, Postaxial, Preaxial, inner, or crossed. Postaxial meaning your thumb or big toe and Preaxial meaning your pinkey finger smallest toe, inner effecting your central fingers or crossed, which is both Postaxial and Preaxial on the same hand(s). Also you can either get Unilateral Polydactyly-occuring on one hand / foot-or Bilateral Polydactyly-occuring on two hands / feet.
Inheritance Pattern
You can either get isolated Polydactyly or Polydactyly as a symptom of another genetic disorder. Some of the disorders that can give Polydactyly as a symptom are-
Polydactyly is caused by an autosomal dominant gene. This means that since the gene is autosomal (not sex-linked), males and females are equally likely to inherit the trait. This also means that since the gene is dominant, children who have only one parent with the trait have a 50% chance of inheriting it. Pluspeople in the same family carrying the same gene can have different degrees of polydactyly. Isolated post-axial polydactyly can be caused by mutations in the GLI3 gene at the location 7p13. Two other gene areas PAPA2 (13q21-q32) and PAPA3 (19p13.2-p13.1) have also been linked to it. The genetics of isolated pre-axial polydactyly are less clear. However, some cases appear to be caused by mutations in the GLI3 gene.
Incidences / Frequencies
African Americans, more than other ethnic groups, can inherit a 6th finger.
Polydactyly can occur once in every 1,000 births.
Polydactyly and Syndactyly are the two most common congenital hand deformities.
Polydactyly is hereditary increasing the chances getting it in isolated families.
In 1/3 of these cases, there is another member of the family with the same condition.
Polydactyly has a prevalence between 5 and 19 per 10 000 live births.
About 80% of cases of Polydactyly are post-axial.
Isolated Postaxial Polydactyly is more common in African-Americans.
Isolated Preaxial Polydactyly is more common in various Asian populations, such as South China, Hong Kong, and Japan.
About 75% -80% of cases of Polydactyly occur as an isolated defect, without any other mental and/or physical abnormalities and about 20%-25% of cases of Polydactyly occur as a feature of a larger genetic disorder.
Treatment / Prognosis
If you find you have Polydactyly or have the gene for Polydactyly, chances are your children might get it and you might not be able to avoid them getting it. Since it can either be part of another disorder or by itself its something that must be surgically fixed other than something being cured. The main treatment of Polydactyly is surgery to remove the extra parts and correct associated problems with what remains. This is sometimes a very complicated surgery, because there might be more to deal with than just skin and a small stalk, twisted bones, crooked joints, missing or extra tendons, nerves, and blood vessels could be there too. The surgery is most likely performed under General anesthesia for children and with either General or IV Sedation with local for Adults. You may also be tested for underlying disorders or conditions if you have not been tested prior. Polydactyly can become more obvious after the surgery, but with careful planning, a hand surgery specialist will attempt to correct these problems at the time of surgery. The underlying possible disorders can be very serious, possibly even bring upon death at an earlier age. The Costs can be quite extensive, usually depending upon the anesthesia choice and the age of the patient. Keep in mind that it could cost 3-6 thousand dollars for the surgery to take place. After surgery, it is usual to protect the hand in a large bandage for weeks to months, depending on what is done. Surgery done in childhood may need to be adjusted for growth with "touch up" surgery when the child is older. The easiest way to find a Surgeon is probably to type “Polydactyly” into a search engine a looking at some sites. One site that shows were you can find a surgeon is at http://www.handcenter.org/
Polydactyly is a condition in which a person has more than five fingers per hand or five toes per foot. Forms of Polydactyly consist of an extra bump at the side of your hand, a finger which widens to end in two fingertips, having five fingers with one thumb (which can seem to be normal from a distance) and an infinite amount of other combonations. The digits may or may not be with shared joints and vessels, nerves, bone etc. and feet / hands may not always be effected at the same time. Polydacyly is also reffered to as something called Supernumerary digits or extra digits. Polydactyly got its name from the ancient greek language, polus-daktulos; polus meaning many, daktulos meaning finger.
Symptoms
Physical problems assiosiated with poldactyly include fingers that are bigger than they should be (bigger than other fingers), Extra digits that are poorly developed and attached by a small stalk that can easily fall off, having problems with malformations inside the hand with the bones rather than having extra digits, or having digits that are smaller than they should be. Limitations consist of hands and feet not being able to fit inside some types of shoes and gloves/mittens, not being able to get a solid grip on certain things, and not being able to have a lot pressure on your hand otherwise, loose digits will fall off or damages can occur. As metioned in the last paragraph, there is almost an infinite amount of different malformation combinations that can occur. However, you can identify it in four ways, Postaxial, Preaxial, inner, or crossed. Postaxial meaning your thumb or big toe and Preaxial meaning your pinkey finger smallest toe, inner effecting your central fingers or crossed, which is both Postaxial and Preaxial on the same hand(s). Also you can either get Unilateral Polydactyly-occuring on one hand / foot-or Bilateral Polydactyly-occuring on two hands / feet.
Inheritance Pattern
You can either get isolated Polydactyly or Polydactyly as a symptom of another genetic disorder. Some of the disorders that can give Polydactyly as a symptom are-
- Asphyxiating thoracic dystrophy
- Carpenter syndrome
- Ellis-van Creveld syndrome (chondroectodermal dysplasia)
- Familial polydactyly
- Laurence-Moon-Biedl syndrome
- Rubinstein-Taybi syndrome
- Smith-Lemli-Opitz syndrome
- Trisomy 13
Polydactyly is caused by an autosomal dominant gene. This means that since the gene is autosomal (not sex-linked), males and females are equally likely to inherit the trait. This also means that since the gene is dominant, children who have only one parent with the trait have a 50% chance of inheriting it. Plus people in the same family carrying the same gene can have different degrees of polydactyly. Isolated post-axial polydactyly can be caused by mutations in the GLI3 gene at the location 7p13. Two other gene areas PAPA2 (13q21-q32) and PAPA3 (19p13.2-p13.1) have also been linked to it. The genetics of isolated pre-axial polydactyly are less clear. However, some cases appear to be caused by mutations in the GLI3 gene.Incidences / Frequencies
Treatment / Prognosis
If you find you have Polydactyly or have the gene for Polydactyly, chances are your children might get it and you might not be able to avoid them getting it. Since it can either be part of another disorder or by itself its something that must be surgically fixed other than something being cured. The main treatment of Polydactyly is surgery to remove the extra parts and correct associated problems with what remains. This is sometimes a very complicated surgery, because there might be more to deal with than just skin and a small stalk, twisted bones, crooked joints, missing or extra tendons, nerves, and blood vessels could be there too. The surgery is most likely performed under General anesthesia for children and with either General or IV Sedation with local for Adults. You may also be tested for underlying disorders or conditions if you have not been tested prior. Polydactyly can become more obvious after the surgery, but with careful planning, a hand surgery specialist will attempt to correct these problems at the time of surgery. The underlying possible disorders can be very serious, possibly even bring upon death at an earlier age. The Costs can be quite extensive, usually depending upon the anesthesia choice and the age of the patient. Keep in mind that it could cost 3-6 thousand dollars for the surgery to take place. After surgery, it is usual to protect the hand in a large bandage for weeks to months, depending on what is done. Surgery done in childhood may need to be adjusted for growth with "touch up" surgery when the child is older. The easiest way to find a Surgeon is probably to type “Polydactyly” into a search engine a looking at some sites. One site that shows were you can find a surgeon is at http://www.handcenter.org/
Resources
No Author. Polydactyly-Genetic Information-AccessDNA. © 2008-2010. Medline Plus. 11 April 2010 __http://www.accessdna.com/condition/Polydactyly/303__
Author not listed. Polydactyly - Overview. 11/2/2009. University of Maryland Medical System. 11 April 2010 __http://www.umm.edu/ency/article/003176.htm__.
Author-N/A. Polydactyly (Extra fingers). © 2007. HandWorld. 11 April 2010 http://www.eatonhand.com/hw/hw024.htm.
Dr Heutink. Clinical and genetic studies on 12 preaxial polydactyly families. 23 June 1998. BMJ journals. 11 April 2010 http://jmg.bmj.com/content/36/1/33.abstract
Gena Tibido. What causes polydactyly?. January 11th, 2010. iNovaa Creations. 11 April 2010. http://bignutshell.com/what-causes-polydactyly/
No Author. Syndactyly and Polydactyly. 04/07/2006. March of Dimes Birth Defects Foundation. 11 April 2010. __http://www.yestheyrefake.net/syndactyly.htm__
Questions